With the higher density and higher integration in recent years of printed circuit boards equipped with transistors, ICs, memory elements, and other electronic components, thermally conductive silicon grease compositions made from an organopolysiloxane and thermally conductive fillers, such as aluminum oxide powder and zinc oxide powder, have been used in order to efficiently dissipate the heat produced from the electronic components (see patent documents 1 to 3). However, a problem with this type of thermally conductive silicone grease composition is that the thermally conductive fillers cannot be filled at a high density, and thus, the heat dissipation property is insufficient.
Meanwhile, a thermally conductive silicone grease composition made from an organopolysiloxane, a thermally conductive filler, and an organohydrogen polysiloxane having at least three silicon-atom-bonded hydrogen atoms per molecule, has been proposed in order to achieve a high density filling of the thermally conductive filler in a thermally conductive silicone grease composition (see patent document 4). However, this type of thermally conductive silicone grease composition has a problem with heat resistance, that is to say, the composition exhibits fluidity through heating, if a thick coating has been carried out, or if coating onto a vertical surface has been carried out. In order to solve this problem, the inventors of this matter proposed a thermally conductive silicone grease composition containing an organopolysiloxane having alkoxysilyl groups bonded via silalkylene bonds to molecular chain termini and the like (see patent document 5). While this thermally conductive silicone grease composition excels in heat resistance and in the suppression of oil bleeding, the problems of thickening or gelation over time arise in some cases, such that further improvements are desired.
Elsewhere, from the viewpoint of improving adhesiveness, or the like, the applicants of this matter proposed a curable organopolysiloxane composition containing an alkoxysilyl-containing group indicated by the formula:

(patent document 6), and set forth a proposition to the effect that an aluminum oxide powder or the like may be optionally contained. However, neither a description nor a suggestion is provided in any form regarding the use of this composition as a thermally conductive silicone composition and the technical effects thereof.